Measles cases have been detected at Newark Liberty International Airport and Boston Logan International Airport during the peak holiday travel season. Health officials are conducting contact tracing for potentially exposed passengers, urging those with symptoms like fever, cough, and rash to call medical providers before visiting. Vaccination is emphasized as the best prevention against the highly contagious virus, which can spread easily in crowded environments. The US has reported over 2,000 cases this year, with concerns rising due to increased travel.